I managed to snag most of Mims III's radio shack books when Tandy (Radioshack UK) closed. these were how I learnt along with 2 equally old model railway electronics books.

I need the 2 way as 1 leg will connect to a mega adk while the other to the official samsung charger. Even with a 2 amp adapter in the mega, I get no response from the mega's coms hence the need to bypass the mega jusst for the power supply!

My SE xperia was the same but I had a base station that provided the bypass, alas the samsung galaxy tab 2 7.0 doesn't have a base station capable of doing this.

So my current problem With the mega adk and Galaxy tab 2 7.0 is down to the tablet not getting enough power.
Instead of chopping into a USB cable to make a scruffy bodged looking thing to supply the extra power,
Is there a prefabricated USB Y cable that has both data and power pass through?
I need one female to two males?

Have you read this? http://flipmu.com/files/2011/04/Demystifying-the-TLC5940.pdf

Also are you using seperate CS (Chip Select) pins of the different chips?

1 get money,
2 Call electrician,
3 Explain the job,
4 Wait for him to do job,
5 Pay up.


or

1 do it yourself
2 Get electrocuted
3 End up in hospital
4 Hope they can save your life!

As people have said - If you don't know how to do it, don't do it!

Have you checked out the RPI web site?
there are already expander boards for the Io's

Im actually interested in this, to see what Ideas I can get for modding my central heating

This stupid fool forgot to recalculate the supply resistor!

Ah the old EPE (Everyday practical Electronics) magazine article. Those were the days. I think I may still have a copy on a backup drive some ware.

As to the mega adk+samsung issue.
If it's what what I think then the problem is the same as what I found with my sony phone.
http://ajb2k3.wordpress.com/2012/06/16/arduino-mega-adk-and-sony-erricson-xperia-mini-pro-x17i-works-well-sort-off/
You need to change the UID and VID in the arduino code.

If you on windows, plug you phone into usb, open device manager and look in the phone properties.
On mac its a bit harder.

So the pcb I use has the power lines running underneath the IC socket, and I find that the only place to put the caps outside of the direct path i.e.,

Power supply > IC socket> capacitor (sorry still trying to work out how to use software)
Will the cap still work like this ?

I recently had a similar accident (slipped with a oscilloscope) and had all light lit an nothing else.
I left it for a few days the redid the wiring. and it looks to be working again.
Im using breadboard and suffered a combination of shorts and loose connection.
Not understanding modern tronics I assume I tripped an internal fuse and had to re set it.

I had the same but with ebay I just ordered 50 of them for 99p
I only need 3 but as it was cheaper to bulk them I now have spares.

Try writing it out as a series of blocks in a flow diagram then translate each block.
I'm following a guide for the TLC5960 which explains how to convert a data sheet into code and i'm surprised how easy it is to do.

Currently running version 152 on OSX 10.8.3 with no problems.!

In one diagram I see them placed between the + supply and the VCC pins

Wrong.

and another diagram put across the + & - supply lines.

Correct.

The capacitor is connected from (A)VCC to GND as close as possible to the chip.

Thats what I thought, thanks.